I can spend between 2-3K I think. I should note that the RPGs I play are no online in case that makes a difference.
Why not built one? Time, Convience, and Prebuilt has a tested config with all compatible parts, etc along with warranty if anything goes wrong.
Sorry. Forgot to add that in the past, when I bought Dell, there were the forums where other people had same computer, so easier to research/fix issues, webite for driver updates, software updates etc.